A three-dimensional simulation method for a transient process of pumped storage power station based on water hammer effect and dynamic mesh theory

Abstract

The invention discloses a three-dimensional simulation method for a transient process of a pumped storage power station based on a water hammer effect and a dynamic grid theory. Firstly, three-dimensional modeling and mesh generation are carried out. Then, the user-defined function is used to add the compressibility equation of state and the function to control the closing of the guide vane in thepump-turbine unit, and the transient solver is used to calculate the fluid in the whole flow channel. Finally, the post-processing software is used to process the calculation results. On the basis ofconsidering the compressibility of the water body and the closing rule of the movable guide vane, 3-D model of the overcurrent system of the whole pumped storage power station is established, including the inlet and outlet, the water pipe and the overflow part of the pump turbine unit, and the transient changes of the internal flow field of the pump turbine unit in the transitional process of thepumped storage power station are intuitively reproduced by using the three-dimensional full-channel simulation model, thus providing a reliable basis for the further study of the pumped storage powerstation.

Description

technical field [0001] The invention relates to a three-dimensional simulation method for the transition process in the overcurrent system of a pumped storage power station, that is, a three-dimensional simulation method for the transition process of a pumped storage power station based on water hammer effect and dynamic grid theory, which belongs to the hydraulic numerical simulation of a pumped storage power station technology field. Background technique [0002] In the actual grid-connected power generation process, the pumped storage power station, as an important means of peak-shaving and valley-filling, will experience several or even dozens of pumping-to-power conversions in a day, among which the power generation condition (turbine condition ) transition process, due to the instantaneous change of flow state, the rapid increase of flow velocity and pressure, etc., it is an extremely dangerous process, and it is also a part that must be focused on when evaluating engi...

AI Technical Summary

Problems solved by technology

Although this method can reduce the calculation amount and ensure the reliability of the calculation results to a certain extent, it is only suitable for simulating various parameters of the pump-turbine unit under steady-state conditions, but for the calculation of the transition process of the pump-turbine unit, Because the flow regime is very complex and changes drastically, the one-dimensional calculation results of the upstream and downstream flow channels of the unit can no longer be used as the boundary conditions for the three-dimensional simulation of the unit section.

If the simplified results are still used as boundary conditions, the calculation results will inevitably be seriously distorted

In addition, in the three-dimensional simulation of the unit section, the water body is considered to be incompressible, which is feasible under stable conditions; but in the transition process, the water body pressure fluctuates sharply due to the rapid change of flow velocity in the flow channel

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